Testing Server Actions

For Vitest mocking patterns (vi.mock(), vi.fn(), mockResolvedValue), see vitest-4/skills/writing-vitest-tests/SKILL.md.

Basic Server Action Test

import { submitContact } from './actions';

test('submitContact validates email', async () => {
  const formData = new FormData();
  formData.set('email', 'invalid');
  formData.set('message', 'Hello');

  const result = await submitContact(null, formData);

  expect(result.error).toBeTruthy();
});